It is well known for indicating product name, characteristic, quantities on the wrapping papers or the products and mainly, as an indication way, a way of printing the barcode, characters and the images on the wrapping papers or the products or a way of attaching label which the barcode, the characters and the images is printed on the wrapping papers or the products is used.
Also, as one of printing ways, there are printout printing, thermal transfer printing, thermosensitive printing and laser printing etc.
The printout printing is to use a thermal printer or ink jet printer and spraying an ink on an outer surface of a film is publicly known and in case of this, printing is erased by happening friction on the way of delivering and sometime it would be happened a malicious behavior erasing already existing printing after that reprinting in order to extend expiration date.
And the thermal transfer printing is a way that a color layer is positioned on a side and it makes the barcode, the characters and the images by thermal element in the middle of a layer which is positioned on the other side.
Also, in case of the thermosentive printing, a heated pin of a printing machine smoothly contacts with a thermosensitive paper what has been treated with a special coating and a color of the heated part is changed into a dot so that it is a recording way of the barcode, the characters and the images.
And the laser printing uses material that it is ash by burning a paper or by a plastic film. Tinted ink is sprayed on ash by burning a paper so that it makes a color layer after then this method projects a laser beam in order to make partially the color layer disappear. This method uses a way that various colors of paper ash prints the barcode, the characters and the images to a laser beam projected area. A laser beam is projected to plastic film ash and this prints the barcode, the characters and the images.
These ways have a drawback that the barcode, the characters and the images are easily erased by friction or chemical material.
The present invention, generally speaking, already has suggested one of solutions in Korean Patent No. 10-0615938.
To further illustrate, this idea provides a method for making non erasable the barcode, the characters, the images label and the barcode that it is consist of making a some part in transparent, making other part of the barcode and the characters in non-transparent, including a loss sheet what an image is printed, making a dark sheet that is attached at the lower part of the loss sheet, projecting a laser beam that it makes the barcode and the characters, the images by that a specific area of the loss sheet is lost and a color of the dark sheet is appeared.
Accordingly, the barcode and the characters, the images use a laser printing way rather than a traditional printing way and make a specific area of a non transparent loss sheet in transparent by projecting a laser beam, make barcode and character by appearing a black color of the dark sheet so that it makes the barcode and the characters, the images not to be damaged by friction or chemical material.
Herein, a loss layer by a laser beam has silver color because this layer made by silver ink that all aluminum particles is included or attached.
A problem by this way is that the barcode and the characters, the image label have a silver color and this cannot satisfy a customer's demand that they want to have various colors.